Magnetic filter with rotary flow



June 7, 1960 w. HETT MAGNETIC FILTER WITH RoTARYTLow Filed 00T.. 3, 1957INVENTOR. MLM/'ANG HEII.

AGENI nited States Patent MAGNETIC FILTER WITH ROTARY FLOW WolfgangHett, Hamburg-Wandsbek, Germany, assigner to North American PhilipsCompany, Inc., New York, N.Y., a corporation of Delaware The presentinvention relates to magnetic filters.

The operation of magnetic filters depends not only upon the magneticvalues but also upon the rate of ow of the medium to be purified.Consequently, the eiciency of a magnetic iilter is improved byincreasing the magnetically active surface and the field strength or bydecreasing the rate of flow of the medium, which is tantamount toincreasing the time during which the magnetic eld is operative. Forstructural and operational reasons, however, limitations are imposedupon these factors.

' -The present invention relates to magnetic filters comprising aseparating member in the form of a cage of magnetically soft material,which tilter serves to free iiuids from particles present therein,without increasing the hitherto usual size of the iilter and withoutadversely alfecting the rates of flow 'of the media, thus increasing theeiiiciency of the filter.

The magnetic filter according to the invention has the feature that themedium to be purified is moved as a rotating turbulent stream or currentpast the separating member, which tlow is broughtabout through aYcylindrical part disposed either before or between the separating memberand a permanent magnet, the size of its apertures being matched to thesize of the particles to be'separated.

According to the invention, the cylindrical part producing the rotaryturbulent ow may advantageously also serve as a mechanical preliminaryfilter by lining or covering the apertures with sieves or a materialacting like a sieve.

In order that the invention may be readily carried into effect, it willnow be described in detail with reference to the accompanying drawing,in which:

Fig. 1 is a longitudinal sectional view of an embodiment of the presentinvention;

Fig. 2, is a cross-sectional view of the embodiment of Fig. 1; and

Fig. 3 is a modification of the embodiment of Fig. 1.

Secured to pole plates 2 and 3 of a permanent magnet, which has beenmagnetized in axial direction, is a cage 4 consisting of soft iron rings5. The cage 4 is surrounded by a sleeve or cylindrical member 6constituting the cylindrical part and provided with longitudinal slots7. At least one edge of the cylindrical member 6 at each of the slots 7is bent to extend at an angle from the surface of said cylindricalmember. The bending angle and the size of each slot are so chosen forpromoting the iiow that the iiuid entering at 8 circulates about theseparating member, that is, the soft iron rings 5, in the form of anevenly rotating stream or turbulent current. The puriiied medium iscarried oii via holes 9 of the pole plate 3 through the outlet 10. Boththe sleeve or cylindrical member 6 and the pole plate 3 may rest on abase plate 11; the pole plate may be secured, for example, by means ofbolts 12.

It is advantageous to provide the inlet opening 8 tangentially withregard to the lter housing 13. `It has,

2. however, been found that a radial inlet opening also yields animproved Afiltering effect. Asa matter of fact, the increase in the rateof flow yields a better separation since the medium is longer exposed tothe magnetically active surfaces. 'A

Therefore, the sleeve 6 may at the same time act as a mechanicalpreliminary filter by lining orcovering the slots or apertures withsieves or with material acting like a sieve, such as, for example, thatshown ascomponent 20 in Pigs. l, 2, and 3. Slots covered with sinteredmaterial proved particularly advantageous.

For cleaning, the filter unit is removed from' the housing. For thispurpose, the cover 14 is removed and th magnetic iilter and the sleeveare taken out. After rinsing and flushing, the sleeve and the magneticfilterv are 'reintroduced into the housing. The base plate 11 may beprovided with a guide slot 15 to receive the sleeve 6, and the baseplatemay be so constructed as to collect any deposits trapped by themechanical preliminary filter in the space 16.

In a modiiied form of the magnetic filter according to the inventionshown in Fig. 3, the cylindrical member 17 in the form of a sleeve isdisposed between the magnet 18 and a soft iron cage 5 surrounding thelatter.

While the invention has been described by means of a specific exampleand yin specific embodiments, I do not wish to be limited thereto, forobvious modificationsI will occur to those skilled in the art withoutdeparting from the spirit and scope of the invention.

What is claimed is:

l. A magnetic filter comprising a housing, a cage-like separatingstructure of magnetizable material positioned in said housing, a magnetpositioned in operative relationship to said structure for providing amagnetic liux in said structure whereby particles in a fiuid to befiltered are attracted to the said structure, means for'sup'plying arotary turbulent stream of said iiuid to said structure, saidlast-mentioned means comprising a substantially cyr lindrical memberpositioned substantially coaxially with said structure in said housingand means for supplying said iluid substantially tangentially to saidmember, said member having a plurality of longitudinal slots therein, atleast one edge of said member at each of said slots being bent to extendat an angle from the surface of the said member, and means for removingsaid fluid from said housing.

2. A magnetic filter comprising a housing, a cage-like separatingstructure of magnetizable material positioned in said housing, a magnetpositioned in operative relationship 'to said structure for providing amagnetic flux in the said structure whereby particles in a iiuid to beiiltered are attracted to the said structure, means'for supplying arotary turbulent stream of said fluid to. said structure, saidlast-mentioned means comprising a substantially cylindrical memberpositioned substantially coaxially with said structure in said housingand means for supplying said iiuid substantially tangentially to saidmember, said member having a plurality of longitudinal slots therein, atleast one edge of said member at each of said slots being bent to extendat an angle from the surface of the said member, mechanical filteringmeans positioned over said slots, and means for removing said uid fromsaid housing.

3. A magnetic filter comprising a housing, a cagelike separatingstructure of magnetizable material positioned in said housing, a magnetpositioned in operative relationship to said structure for providing amagnetic diux in the said structure whereby particles in a uid to befiltered are attracted to the said structure, means for supplying arotary turbulent stream of said fluid to said structure, saidlast-mentioned means comprising a substantially cylindrical memberpositioned substantially cot I 3 n...

and means for supplying said fluid substantially tangentially to saidmember, said member having a plurality of longitudinal slots therein, atleast one edge of said member at each of said slots being bent ytoextend at an angle from the surface of the said member, and meansI forremoving said fluid from said housing.

4. Av magnetic filter comprising a housing, a cagelike separatingstructure of magnetizable material positioned in said housing, a magnetpositioned in operative relationship to said structure for providing avmagnetic ux in the said structure whereby particles in a uid to befiltered are attracted to the said structure, means for supplying arotary turbulent stream of said fluid to said structure, saidlast-mentioned means comprising a substantially cylindrical memberpositioned substantially coaxially with and around said structure insaid housing and means for supplying said .fluid substantiallytangentially to said member, said Amember having a plurality oflongitudinal slots therein, at least one edge of said .member at each ofsaid slots being bent to extend at an angle from the surface of the saidmember, mechanical filter-ing means positioned over said slots, andmeans .for removing said fluid from said housing.

S` A magnetic lter comprising a housing, a cagelike separating structureof magnetizable material positioned `in said housing, a magnetpositioned in operative relationship .to said `structure for providing amagnetic ux in the said structure whereby particles in a fluid to befiltered are attracted to the said structure, means -for supplying arotary turbulent stream of said uid to said structure, saidlast-mentioned means comprising a subF stantially cylindrical memberpositioned substantially coaxially with and interposed between saidmagnet and said structure in saidhousing and means for supplying saidfluid substantially tangentially to said member, said inember having aplurality of longitudinal slots therein, at least one edge of saidmember at each of said slots being bent to extend at an angle Afrom thesurface of the said member, and means for removing said fluid from saidhousing..

6. A magnetic filter comprising ahousing, a cagelike separatingstructure of magnetizable material posi-V tioned in said housing, -amagnet positioned substantially coaxially with and inside said structurefor providing a magnetic flux in the said structure whereby particles ina uid to be filtered are attracted to the said structure, means forsupplying a rotary turbulent stream of said fluid to said structure,said last-mentioned means comprising a substantially cylindrical memberpositioned substantially coaxially with and interposed between saidmagnet and said structure in said housing and means for supplying saidfluid substantially tangenti-ally to said member, said member havingV aplurality of longitudinal 'slots therein, at least one edge of saidmember at each of said slots being bent to extend at an 'angle from thesurface of the said member, and means for removing said uid from saidhousing.

7. A magnetic filter comprising a housing, a cagelike separatingstructure of magnetizable material positioned in said housing, a magnetpositioned substantially coaxially with and inside said structure forproviding a magnetic flux in the said structure whereby particles in afluid to be filtered are attracted to the said structure,

Vmeans for 'supplying a rotary turbulent stream of said uid to saidstructure, said lastmentioned means comprising a substantial'iycylindrical member positioned substantially coaxially with andinterposed between said magnet and said structure in said housing andmeans for supplying said tluid Substantially tangentially to saidmember, said member having a plurality of longitudinal slots therein, atleast one edge of said member at each of said slots being bent to extendat an angle from the surface of the said member, mechanical filteringmeans positioned over said slots, and means for removing said duid fromsaid housing.

References Cited in the le of this patent UNITED STATES PATENTS1,425,366 Chapman Aug. 8, 1922 2,317,774 Kiek et al. Apr. 27, 19342,732,943 Hagbe'rg J'an. 31, 1956 FOREIGN PATENTS l272,784 Great BritainJune 23, 1927 4UNITED lST'ATE'S PATENT OFFICE CERTIFICATE 0F CORRECTIUNPatent No. 2,939,583 June 7g 1960 Wolfgang Hett It is hereby certifiedthat error appears in the above numbered patent requiring correction andthat the said Letters Patent should read as corrected belowD In theheading to the printed specification, line TQ for "Claims priority,application Germany Oct.. 26, 1956" read Claims priority, applicationGermany Oct, 22 1956 Signed and sealed this 20th day of December 1960..

(SEAL) Attest:

KARL H. AXLINE Attesting Officer 'ROBERT C- WATSON Commissioner ofPatents

